Aqueous hydraulic cement slurry

ABSTRACT

An aqueous hydraulic cement slurry is disclosed which comprises water, a hydraulic cement, a surfactant and, as a fluid loss additive, epihalohydrin derivatives of polyalkylenepolyamines.

BACKGROUND OF THE INVENTION

The present invention concerns aqueous hydraulic cement slurrycompositions.

Hydraulic cements, i.e., any inorganic cement that hardens or sets underwater, are customarily admixed with water and emplaced as aqueousslurries. The amount of water employed may vary rather extensivelydependently largely upon the fluidity of the slurry required and uponthe necessary ultimate strength. In a great many uses of a hydrauliccement it is necessary for the cement slurry to be emplaced within ornext to a porous medium, for example, earthen strata, e.g., in thecementing off of boreholes, grouting, dam and tunnel construction andthe like. When such is the case water filters out of the slurry and intothe strata during the setting period. When this occurs to anyappreciable extent there usually results an uncontrolled setting rate,improper placement, impaired strength properties and usually acontamination of the surrounding strata. All of these undesirableconditions are especially to be avoided in cementing operationsassociated with oil, gas, water or brine wells. In an effort to lessenthe loss of fluid from an aqueous hydraulic cement slurry variousmaterials have been employed. One such material comprises a polyaminecompound selected from the class consisting of polyalkylenimines,polyalkylenepolyamines and mixtures thereof. A description of thesepolyamine compounds and their use in hydraulic cement slurries istaught, for example, in U.S. Pat. No. 3,491,049, the teachings of whichare specifically incorporated herein by reference. Although thesepolyamino compounds are quite satisfactory in environments wherein thetemperature of the hydraulic cement slurry does not increase to aboveabout 200° F., the fluid loss characteristics of these cement slurriesare unacceptable at higher temperatures.

U.S. Pat. No. 4,131,578 discloses fluid loss additive compositionssuitable for use at temperatures of 200° F. and above.

The present invention provides for fluid loss additives which are moreefficient, i.e. they require less active additive to achieve the samelevel of water loss or at the same level of active additive less waterloss occurs while also providing more stable, non-settling, cementslurries.

SUMMARY OF THE INVENTION

The present invention pertains to an improvement in aqueous hydrauliccement slurry compositions comprising water, hydraulic cement,surfactant and polyalkylenepolyamine fluid loss additive wherein saidimprovement resides in the use of, as said fluid loss additive, at leastone composition prepared by reacting

(A) at least one composition prepared by reacting

(1) a polyalkylenepolyamine composition having an average molecularweight of from about 60 to about 500, preferably from about 150 to about300 with

(2) at least one alkylene dihalide with

(B) at least one of

(1) an epihalohydrin or dihalohydrin,

(2) an adduct of

(a) an epihalohydrin or dihalohydrin and

(b) an alkylenediamine, polyalkylenepolyamine having an averagemolecular weight of from about 60 to about 500, preferably from about100 to about 300 or mixtures thereof or

(3) mixtures thereof; and wherein

(C) component (A-1) and (A-2) are reacted in quantities such that thequantity of A-2 used is less than the amount needed to form a gel by anamount (expressed as weight of carbon and hydrogen contained in A-2) offrom about 0.8% to about 5% of the weight of carbon plus hydrogen plusnitrogen present in the reaction mixture when a gel would be formed;

(D) components (A) and (B) are employed in quantities which provide apolyamine which gives a fluid loss of less than 60 ml, preferably lessthan about 45 according to the API RP 10B fluid loss test described inthe examples.

The viscosity of a solution containing 35% active material is usuallyfrom about 300 to about 10000, preferably from about 2000 to about 4000cps.

In determining the amount of the polyalkylenepolyamine and alkylenedihalide to employ, a series of lab scale reactions are employed withvarying ratios of reactants of alkylene dichloride:polyalkylenepolyaminesuch as, for example, 0.4:1, 0.5:1, 0.6:1, 0.8:1 and 1.1:1 by weight areconducted at a suitable temperature and water concentration. From thelowest ratio that created the gel new proportions are selected in thefollowing manner, assuming a ratio of 0.55:1 produced a gel.

The quantity of reactants to be employed can be calculated as follows:

Assume the following formulation produces a gel.

    ______________________________________                                               1100 g EDC (ethylene dichloride)                                              2000 g polyamine                                                              3900 g water                                                                  7000                                                                   ______________________________________                                    

grams active (carbon, hydrogen, nitrogen) contained in above formulation

    ______________________________________                                                  2000 from polyamine                                                            311 from EDC                                                                 2311                                                                ______________________________________                                    

The amount of carbon plus hydrogen to leave out of the recipe is fromabout 19 g to 115 g which corresponds to 67 to 406 grams of EDC.

The amount of crosslinking agent to be further added is determined byadding small portions of crosslinking agent to about 100 grams of thefirst product until the product gels. At that point (assume 6 grams of50% active crosslinking agent produced the gel) a series of samples areprepared using 6 g/100 g, 5 g/100 g, 4 g/100 g, etc. The ratio whichgives a product with a viscosity of 1000-4000, preferably 2000-3000, cpsis the one which would be used to complete the reaction.

DETAILED DESCRIPTION OF THE INVENTION

Suitable polyalkylenepolyamines which can be employed herein includepolyethylenepolyamines having an average molecular weight of from about60 to about 500 which can be prepared by reacting a vicinal alkylenedihalide having from 2 to about 6 carbon atoms with ammonia or lowerpolyalkylenediamines such as, for example, ethylenediamine,diethylenetetramine and the like. Suitable methods of preparation aredisclosed by Garms et al in U.S. Pat. No. 3,210,308 which isincorporated herein by reference. Particularly suitable are the bottomsproduct from the preparation of ethylenediamine from ammonia andethylene dichloride. By bottoms product it is meant that which resultsafter substantially removing these compounds boiling lower thanpentaethylenehexamine from the reaction product resulting from reactingammonia with ethylene dichloride.

Suitable epihalohydrins and/or dihalohydrins which can be employedherein include those represented by the formulas ##STR1## wherein each Ris hydrogen or an alkyl group having from 1 to about 4 carbon atoms andeach X is independently chlorine or bromine.

The cement slurry also contains an effective amount of a surfactant suchas, for example, a water dispersable lignosulfate, lignoamine, sulfonicacids, mixtures thereof and the like.

If desired the cement slurry compositions may also contain a borate ionreleasing compound and/or a carbonate and/or a bicarbonate as disclosedby Crinkelmeyer et al in U.S. Pat. No. 4,131,578 which is incorporatedherein by reference.

The quantities of components of the aqueous cement slurry composition ofthe present invention are based on 100 parts by weight of hydrauliccement as follows:

hydraulic cement--100

water--about 25 to about 100, preferably about 35 to about 50

fluid loss additive--about 0.5 to about 8, preferably about 0.75 toabout 3

surfactant--about 0.25 to about 5, preferably about 0.5 to about 1.5

borate ion releasing compound--0 to about 3, preferably about 1 to about2

carbonate or bicarbonate--0 to about 3, preferably 0.1 to about 0.3

The following examples are illustrative of the invention but are not tobe construed as to limiting the scope thereof in any manner.

EXAMPLE 1 A. Preparation of Polyalkylenepolyamine

Water, 2200.4 g and 1289 grams of a polyalkylenepolyamine which was thebottoms product resulting from removing tetraethylene pentamine andlower boiling products from the reaction product of ammonia and ethylenedichloride and having an average molecular weight of about 300 andhereafter referred to as polyamine 300 were mixed in a 5-liter flask.Ethylene dichloride (510.5 g) was added to the flask. The mixture ofreactants was stirred and heated at 70° C. for 16 hours (57600 s). Theviscosity of the resultant solution was <300 cps.

B. Preparation of Crosslinker

Diethylenetriamine, 82.54 g, and 176 g of water were placed in a 1-literflask. The temperature of the solution was controlled at about 40° C.while 370.14 g of epichlorohydrin was added. The reactants were stirredovernight at 40° C. and a light yellow product was removed from theflask and refrigerated.

C. Preparation of Crosslinked Polymer

Crosslinker solution prepared in B above, 134 g, was added to 4000 g ofthe polyalkylenepolyamine prepared in A above. The mixture of reactantswas heated at 60°-70° C. for 4 hours (14400 s). An amber solution with aviscosity of about 300 cps was removed from the flask. This material wastested as indicated in D below. The results are reported in Table I.

D. Fluid Loss Testing

The fluid loss tests were run according to API RP 10B using a Baroidhigh temperature high pressure fluid loss apparatus and a 325 mesh (U.S.Standard Sieve Series) stainless steel screen. Lone Star type H cement,100 parts by weight, was mixed with 0.5 pbw of a surfactant materialwhich is the condensation product of formaldehyde andmononaphthalenesulfonic acid. Water, 42 pbw, was mixed with the desiredamount of the active polyamine (1.1% by weight of the cement employed).The water and cement were then blended together and digested at 200° F.(93.3° C.) for 20 minutes (1200 s). The slurry was added to thefiltration cell which was preheated to 200° F. (93.3° C.) and the fluidloss, cc in 30 min. (1800 s), was measured with 1000 psig (6.89 kPa)nitrogen pressure on the filtration cell. The fluid loss measure wasthen multiplied by 2 so as to adjust for the size of the screen usedwith the filtration cell.

EXAMPLE 2 A. Preparation of Crosslinker

Polyamine 300, 503.5 g, and 825.5 g of water were placed in a 1-literflask. The temperature of the solution was controlled at 30° C. while1858 g of epichlorohydrin was added. The reactants were stirred at 70°C. overnight and an amber product was removed from the flask.

B. Preparation of Crosslinked Polymer

Crosslinker solution prepared in A above, 10.3 g was added to 150 g ofpolyalkylenepolyamine prepared as in Example 1-A. The mixture ofreactants was heated at 60°-70° C. for 4 hours (14400 s). An ambersolution was removed from the flask. It was tested as a fluid lossadditive by the procedure described in Example 1-D. The results aregiven in Table I.

EXAMPLE 3

To 300 g of polyalkylenepolyamine prepared in Example 1-A was added 8 gof epichlorohydrin. The mixture was reacted in a 60° C. shaker bothovernight. An amber solution was produced. This material was testedaccording to Example 1-D. The results are given in Table I.

EXAMPLE 4

To 250 g of Polyamine 300 was added 640 g of water. Epichlorohydrin, 127g was added and reacted therewith until the viscosity increased to >3000cps. The resultant product was tested as a fluid loss additive accordingto the procedure of Example 1-D. The results are given in Table I.

EXAMPLE 5 (COMPARATIVE)

Example 4 was repeated employing 1200 g of Polyamine 300 and 618 g ofethylene dichloride. The resultant viscosity was <6000 cps. The productwas tested as a fluid loss additive employing the procedure of Example1-D. The results are given in Table I.

                  TABLE I                                                         ______________________________________                                        EXAMPLE NO.                                                                              FLUID LOSS IN CUBIC CENTIMETERS*                                   ______________________________________                                        1-A        >60 mls in <5 min.                                                 1-C        20                                                                 2-B        20                                                                 3          26                                                                 4          26                                                                 5            70.4                                                             ______________________________________                                         *corrected to API standard screen, i.e. the test results have been            multiplied by 2.                                                         

We claim:
 1. In aqueous hydraulic cement slurry compositions comprisingwater, hydraulic cement, surfactant and polyalkylenepolyamine fluid lossadditive; the improvement which comprises employing as said fluid lossadditive, at least one composition prepared by reacting(A) at least onecomposition prepared by reacting(1) a polyalkylenepolyamine compositionhaving an average molecular weight of from about 60 to about 500 with(2) at least one alkylene dihalide with (B) at least one of(2) anepihalohydrin or dihalohydrin, (2) an adduct of(a) an epihalohydrin ordihalohydrin and (b) an alkylenediamine, polyalkylenepolyamine having anaverage molecular weight of from about 60 to about 500 or mixturesthereof or (3) mixtures thereof; and wherein (C) component (A-1) andcomponent (A-2) are reacted in quantities such that the quantity of A-2used is less than the amount need to form a gel by an amount (expressedas weight of carbon and hydrogen contained in A-2) of from about 0.8% toabout 5% of the weight of carbon plus hydrogen plus nitrogen present inthe reaction mixture when a gel would be formed; (D) components (A) and(B) are employed in quantities which provide a polyamine which gives afluid loss of less than 60 ml, according to the API RP 10B fluid losstest described in the examples.
 2. An aqueous cement slurry compositionof claim 1 wherein(i) component (A-1) has an average molecular weight offrom about 150 to about 350; (ii) component (A-2) is ethylenedichloride; (iii) components (B-1) and (B-2-a) are epichlorohydrin; (iv)component (B-2-b) has an average molecular weight of from about 60 toabout 150; (v) components (A) and (B) are employed in quantities whichprovide a polyamine which gives a fluid loss of less than about 45 mlaccording to the API RP 10B fluid loss test described in the examplesand the viscosity of a solution containing 35% active material is fromabout 2000 to about 4000 cps.
 3. A composition of claim 1 wherein theviscosity of a solution of components (A) and (B) containing 35% activematerial is from about 300 to about 10000 cps.
 4. A composition of claim2 wherein the viscosity of a solution containing 35% active material isfrom about 300 to about 10000 cps.